Traditionally, theater production companies use 7×19 or 19×7 wire ropes for stage rigging applications to move actors around the stage. Such wire ropes are usually bright and reflect light so theater production companies or rope manufacturers will often coat the bright wire ropes with black powder to prevent the audience from easily detecting the ropes when used on performers. However, coating the rope with black powder often results in the black powder flaking off during the operation of the rope in the rigging system of pulleys and blocks commonly used in theater productions. Therefore, it would be beneficial to produce a wire rope for use in theatrical productions that has a blackened finish that will not wear or flake off during normal use of the ropes.
Traditional 7×19 or 19×7 wire ropes tend to rotate when under a tensile load which can result in dangerous conditions for performers. A “birdcage” failure of wire rope occurs when the outer strands of a rope balloon outwards taking the shape of a birdcage. This is sometimes due to shock loading. This birdcage effect exposes the core of the wire rope or allows it to pop or move out of position which can be dangerous for the performers. In addition, traditional ropes are subject to excessive rotation thereby rendering them unsuitable for use with swivels attached to the ends of the rope. Such swivels are often used in single part lifts in theatrical productions. Therefore, it would be beneficial to produce a birdcage-resistant and/or a rotation-resistant rope for use in theatrical productions.
Finally, in most theatrical productions, the actors wear elaborate and expensive costumes. If any kind of lubricant is added to the wire rope, the lubricants can rub off and ruin the costumes. However, wire rope will rust rapidly if not lubricated and, in turn, cause premature fatigue failure. Therefore, it would be beneficial to produce a non-lubricated wire rope that will not rust rapidly.